Condition based maintenance

I have wireless sensors that can transmitt real time data back to a centralized computer where the readings are stored in a database. The data is also checked against threshold values to determine if something has failed. I would like to look into more advance maintenance algorithms. For example how can the sensor readings predict when a piece of equipment will need to be serviced? When is the optimum time to replace a part? Can someone suggest ideas of where I can get information about this topic? ThanK you.